Facade structures of the type mentioned above are known in the prior art in a wide variety of embodiments. To produce the insulating layer used to provide thermal insulating, rectangular insulating panels with a flat, supporting outer surface are glued to a load-bearing underground, such as the outside wall of a building, using lumps of mortar or by applying a tile adhesive to the entire surface. Then, the tile covering is mounted to the outside of the insulating layer, the covering providing rain protection and protecting against other atmospheric effects and against mechanical damages, and providing an exterior design.
According to a first variant in the prior art, the installation of the tile covering first involves the application of a reinforced inner wall onto the insulating layer, the inner wall normally having a total thickness of between 25 and 35 mm. Then, the tile elements can be glued to the inner wall using a cement-like tile adhesive. Alternatively, a decoupling mat can first be attached to the inner wall using a cement-like tile adhesive, the mat also being additionally securable using dowels, whereupon the tile elements are glued to the decoupling mat. The purpose of the decoupling mat is to prevent the transfer of stresses from the inner wall to the tile elements or from the tile elements to the inner wall. A disadvantage of this variant is first of all that the application of the reinforced inner wall is time- and cost-intensive. Furthermore, plastics and calcium carbonate can bleed out from the tile adhesive, which leads to visually unpleasant deposits. Also, according to DIN 18515-1, which applies to mortared tiles or tiles with a surface area of ≤0.12 m2, a side length of ≤0.40 m and a thickness of ≤0.015 m, tile elements with format sizes of more than 30×40 cm may not be used, at least nominally.
In an alternative variant of the prior art, the tile covering is mounted using metal support systems that are dowelled to the load-bearing underground of the facade structure, wherein the individual tile elements are fixed to the support system by way of special anchors. An advantage of such support systems is that they can be installed at a pre-determined distance from the insulating layer so that the tile covering is ventilated from behind. However, there is a disadvantage in that the tile elements have to be relatively thick if the anchors are to engage in slots or holes made in the side edges or on the back side of the tile elements, as seen in publication DE 40 04 103 A1, for example. For thinner tile elements, support brackets are normally used, but they reach around the surface of the tile elements that are visible from the outside, negatively affecting the appearance of the facade structure. Another disadvantage is that the joints between adjacent tile elements remain open in these types of support systems so that rainwater, for example, can get behind the tile covering. Also, open joints are not always desirable when it comes to visual appearances. Moreover, the insulating layer is interrupted by the anchoring of the support structures at the load-bearing underground of the facade structure, which leads to undesirable thermal bridges. Lastly, such support systems are very cost-intensive.